1. Field of the Invention
The invention relates to a streamlined profile reducing the speed deficit in its wake, a pylon comprising such a profile, a propulsion assembly including such a pylon and an aircraft comprising such a profile or such a propulsion assembly.
During a flight, the pylon bearing the engine generates a wake, and this irrespective of the design of the pylon.
This is due in particular to the fact that since the height of the boundary layer of its profile increases in the direction downstream from the profile, a “speed deficiency” occurs at the trailing edge, expressed by a difference between the speed of the free air flow and the local speed of the air in the zone downstream from the profile.
The zone having this speed deficiency also is the seat of an air “mass flow deficiency.” For this reason, the air has a tendency to be carried along in the zone with speed deficiency, thus causing turbulences.
The discontinuity of the speeds and the turbulences of the wake cause, among other things, an increase in the noise generated by the propellers of the turbine that may impair the comfort of the passengers and the environment. They also cause vibrations increasing the fatigue sustained by the engine, the systems carried in the pylon and the actual structure of the aircraft.
2. Description of the Related Art
Solutions have been developed in the past to remedy this speed deficit of the wake of the pylon.
One of them, set forth in particular in the document U.S. Pat. No. 5,156,353, consists in blowing air from a high-pressure source close to the trailing edge of the profile of the pylon so as to eliminate the air-flow deficit and therefore reduce the speed deficit.
This solution, however, involves the need to carry out a substantial drawing of pressurized air from a component of the aircraft such as the engine compressor, which has the effect, among other things, of complicating its design.
Another disadvantage of this solution lies in the need to provide a system of pipes conveying the air from the compressor to the trailing edge of the profile of the pylon, which complicates the design even more and is expressed by an additional weight.